No Sound Output From Avh-x4500bt

Hello,I am contacting you today because my head unit is no longer working. I ordered a Pioneer AVH-X4500BT 2-DIN Multimedia DVD Receiver with 7 In. Touchscreen Display and Bluetooth back in July 2013.The head unit was working properly up until December 2013. It started out as working fine on start up, then after about 30 minutes it would just cut sound output. Display worked fine, all BT connections were intact, but there was no sound output to the speakers. After this first occurrence it happened consistentntly every time I started the car. After about a week or so the 30min cut off was slowly reducing to 10 minutes, then 5 minutes, 30 seconds, 5 seconds, and then about a month ago it just flat out would not play sound from start up. The head unit would power up, it would send a crackle to the speakers, then no sound. I went in and double checked all my connections, they are all 100%. The weirdest part about this is I went on a trip for 12 days in January and the car sat unused the entire time. When I returned, I started up the car and the head unit was working fine, clear sound to all the speakers. This lasted for about 5 mins, then a crackle and stopped working. Since then it hasn't made a sound, until today, the car had been on for several minutes, out of nowhere the radio started playing, 30second then cutout again.Please help me figure out what is going on here! It's so frustrating to pay so much for a high quality item for it to not last more than 4 months!!!!Thank you for your time.